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AbstractThe COVID-19 pandemic has deepened the effects of socioeconomic status (SES) and wellbeing (WB) on students’ academic achievement, particularly in developing countries; thus, it becomes necessary to understand the nature of these concurrent relationships. This study aimed to explore the relationships between SES, WB and academic achievement, based on the data from the Programme for International Student Assessment (PISA) in 2018 within the Turkish context. In this cross-sectional study, we used hierarchical multiple linear regression analysis to explore how the independent variables predicted academic achievement in blocks based on data from 6890 students attending 186 schools. The study revealed that the model, including the independent variables, predicted students’ achievement in reading, mathematics and science; however, the prediction level of demographic factors and domains of WB were very low, while SES had the highest prediction level. The results offer insights into the predictors of academic achievement and educational inequalities in the context of a developing country.

The two main purposes of the current meta-analysis were (a) to determine the relation between socioeconomic status (SES) of students and academic performance (AP) (b) and evaluate the effect of several potential moderating factors in this relation. Data covered the publications between 2010 and 2019, and the dataset consisted of 48 independent studies that included 62 different samples, and the total sample was 386.601. Findings revealed that the relation between SES and academic performance represented a moderate positive correlation. All moderators, type of SES measure, academic performance scale, location, grade level, subjects of academic performance, and year, produced significant effects, respectively. These findings were discussed for every category of moderators with the related literature.

A considerable amount of literature has been published on students’ well-being, but empirical research has yielded ambiguous results regarding the relationship between well-being and academic achievement. Meta-analysis studies on this issue are scarce, and the available studies focus on a single domain of well-being. Meta-analyses investigating students’ general well-being and academic achievement are needed. To this end, we carried out a meta-analysis study on the association between students’ general well-being and academic achievement based on data from correlational studies involving 54,426 participants in 81 independent samples. We report a significant and positive but small effect size based on this dataset. The effect sizes differ significantly in terms of the moderator variables of publication year, age, school level, and publication type, while the correlation is robust across well-being domains, academic areas, scale types, and development levels of countries. Results are discussed and implications are suggested in line with the literature.

Retraction statement The publishers of International Journal of Numerical Methods for Heat & Fluid Flow wish to retract the article Şenay, G., Kaya, M., Gedik, E. and Kayfeci, M. (2019), “Numerical investigation on turbulent convective heat transfer of nanofluid flow in a square cross-sectioned duct”, International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 29 No. 4, pp. 1432-1447. https://doi.org/10.1108/HFF-06-2018-0260 An internal investigation into a series of submissions has uncovered evidence that the peer review process was compromised. As a result of these concerns, the findings of the article cannot be relied upon. This decision has been taken in accordance with Emerald’s publishing ethics and the COPE guidelines on retractions. The authors of this paper would like to note that they do not agree with the content of this notice. The publishers of the journal sincerely apologize to the readers.

ABSTRACTThe aim of this study is to research whether interval running or 4×4 narrow field practices is a more effective training method for developing aerobic capacity, anaerobic power, strength, speed, flexibility and technical capacity of children during preparation season. Children have been randomly divided into three groups as “Narrow Field Practice Group (NFP)” (n=8), “Interval Running Group (IR)” (n=8) and “Control Group (CG)” (n=8). Aerobic capacity, speed, leg strength, vertical jump, flexibility, anaerobic power, body mass index and football technical scores of children were measured then for the duration of six weeks. NFP and IR groups participated in 4×4 minutes and 3 days a week narrow field practices and interval running practices. CG participated in low intensity training and final measurements were taken. SPSS was used in analyzing the data acquired. Values acquired as a result of preliminary, final tests were statistically compared with help of ANNOVA test. As a result of the study, significant increase was observed in VO2max, passing and dribbling values of NFP and IR groups, sprint, juggling on feet and knee, passing and dribbling values of NFP group.

The design and application of morphing systems are ongoing issues compelling the aviation industry. The Clean Sky - program represents the most significant aeronautical research ever launched in Europe on advanced technologies for greening next-generation aircraft. The primary purpose of the program is to develop new concepts aimed at decreasing the effects of aviation on the environment, increasing reliability, and promoting eco-friendly mobility. These ambitions are pursued through research on enabling technologies fostering noise and gas emissions reduction, mainly by improving aircraft aerodynamic performances. Within the Clean Sky framework, a multimodal morphing flap device was designed based on tight industrial requirements and tailored for large civil aircraft applications. The flap is deployed in one unique setting, and its cross section is morphed differently in take-off and landing to get the necessary extra lift for the specific flight phase. Moreover, during the cruise, the tip of the flap is deflected for load control and induced drag reduction. Before manufacturing the first flap prototype, a high-speed (Ma = 0.3), large-scale test campaign (geometric scale factor 1:3) was deemed necessary to validate the performance improvements brought by this novel system at the aircraft level. On the other hand, the geometrical scaling of the flap prototype was considered impracticable due to the unscalability of the embedded mechanisms and actuators for shape transition. Therefore, a new architecture was conceived for the flap model to comply with the scaled dimensions requirements, withstand the relevant loads expected during the wind tunnel tests and emulate the shape transition capabilities of the true-scale flap. Simplified strategies were developed to effectively morph the model during wind tunnel tests while ensuring the robustness of each morphed configuration and maintaining adequate stiffness levels to prevent undesirable deviations from the intended aerodynamic shapes. Additionally, a simplified design was conceived for the flap-wing interface, allowing for quick adjustments of the flap setting and enabling load transmission paths like those arising between the full-scale flap and the wing. The design process followed for the definition of this challenging wind tunnel model has been addressed in this work, covering the definition of the conceptual layout, the numerical evaluation of the most severe loads expected during the test, and the verification of the structural layout by means of advanced finite element analyses.

AbstractThis study was conducted to define the effects of an 8-week plyometric training program on anaerobic capacity, leg strength, vertical jumping and speed values in female futsal players. The study was conducted on 20 volunteer futsal players playing for the top teams of the 2013-2014 season of the Interuniversity League. 20 players futsal players were randomly assigned to the experimental group (n=10), and control group (n=10). The Wingate anaerobic test was used to measure anaerobic power and capacity, a dynamometer was used to measure leg strength, and the Newtest Powertimer measurement device was used to measure the players’ 30-meter sprint and vertical jumping values. The multivariate analysis of variance (MANOVA) method was used for statistical analysis. A statistically significant difference was observed in the following factors among the female futsal players of leg power (F (1.36)= 4.20, p= 0.05), absolute peak power (F (1.36)= 6.61, p= 0.01), absolute mean power (F (1.36)= 4.77, p= 0.04), vertical jump (F (1.36)= 14.73, p= 0.00), and speed (F (1.36)= 14.28, p= 0.00). In conclusion, this 8-week training program increased the abovementioned factors in female futsal players.

In this study we investigated the dynamical behavior of aircraft wings and using piezoelectric actuation we implemented active vibration control. The aircraft wing is modeled as a thin-walled composite beam having a cross section of diamond shaped. The dynamic response of the beam under varying proportional and velocity feedback gain parameters is obtained and shown to be enhanced with optimal control procedure, minimizing the control effort and response.

In this paper, vibration analysis of a blade modeled as an anisotropic composite thin-walled beam is carried out. The analytical formulation of the beam is derived for the flapwise bending, chordwise bending and transverse shear deformations. The equations of motion are solved by applying the extended Galerkin method (EGM) for anti-symmetric lay-up configuration that is also referred as Circumferentially Uniform Stiffness (CUS). Consequently, the natural frequencies are validated by making comparisons with the results in literature and it is observed that there is a good agreement between the results. Combined effects of transverse shear, fiber orientation, and rotational speed on the natural frequencies are further investigated.

Abstract: In this study, free vibration analysis of a rotating, double tapered Timoshenko beam featuring coupling between flapwise bending and torsional vibrations is performed. At the beginning of the study, kinetic and potential energy expressions of a rotating Timoshenko beam having single cross-sectional symmetry are derived in a detailed way by using several explanatory tables and figures. In the following section, Hamilton’s principle is applied to the derived energy expressions to obtain the governing differential equations of motion. The parameters for the hub radius, rotational speed, rotary inertia, shear deformation, slenderness ratio, bending–torsion coupling and taper ratio are incorporated into the equations of motion. In the solution part, an efficient mathematical technique, called the differential transform method (DTM), is used to solve the governing differential equations of motion. Using the computer package, Mathematica, the mode shapes are plotted, the effects of the incorporated parameters on the natural frequencies are investigated. The calculated results are tabulated in several tables and plotted in several graphics. [Copyright &y& Elsevier]

AbstractLiquids may be used between the magnetic confined fusion plasma and the first wall of the plasma chamber to reduce the material damage through displacements per atom (dpa) and helium gas production. This could extend the lifetime of the first wall in a magnetic fusion energy (MFE) reactor to a plant lifetime of ~30 yr.Neutronic calculations are carried out in S16P3approximation for a typical HYLIFE-II blanket geometry, an inertial fusion energy (IFE) reactor design. This provides a comparison of the damage data between compressed and uncompressed targets, for IFE and MFE applications, respectively, by using Flibe (Li2BeF4), natural lithium, and Li17Pb83eutectic as both coolant and wall protection. In the consideration of mainline design criteria, including sufficient tritium breeding ratio (TBR = 1.1), material protection (dpa < 100 and He < 500 parts per million by atom in 30 yr of operation), and shallow burial index, coolant zone thickness values are found to be 60 cm for Flibe, 171 cm for natural lithium, and 158 cm for Li17Pb83with Type 304 stainless steel (SS-304) as structural material.Material damage investigations are extended to structural materials made of SiC and graphite for the same blanket to obtain waste material suitable for shallow burial after decommissioning of the power plant.The dpa values and helium production rates in graphite are comparable to those in SS-304. However, they are higher in SiC than in SS-304 and graphite.The average neutron heating density in the external 1.6-mm-thick SS-304 shell of the investigated blanket beyond the SiO2insulation foam decreases rapidly with increasing thickness of the Flibe coolant. With DR= 60 and 80 cm, it becomes only 594 and 95 μW/cm3, respectively. The design limit for heat generation density in superconducting coils for magnetic fusion is 80 μW/cm3. A very important result of this work is that a blanket with liquid-curtain protection would not require extra shielding for superconducting coils around the fusion plasma chamber. This could result in an important simplification of the design.